Standard telephone switching equipment like a private branch exchange (PBX) or an automatic call distributor (ACD), typically are equipped with two (2) standard interfaces. One interface would be a standard line printer interface, which is used for the piece of equipment to log error conditions and changes in status and changes in configuration. A second standard interface on most equipment is an ASCII dumb terminal interface to drive a VT 100 style dumb terminal which a technician can use to query an error buffer and also to make changes in the configuration of the system to take on line or off line certain functionalities in the switch.
The main problem with the standard equipment is that all checking and testing must be done locally. In order for a technician to even query an internal buffer or to read the printer output, the technician must physically be present at the same location as the PBX or the ACD. This co-location requirement causes a time problem in that the technicians may be geographically scattered from the equipment that they maintain, and time is lost relocating to the equipment site.
Two known solutions to this problem is to have either an on-site technician permanently assigned to monitor the equipment, or have a visiting technician that makes periodic inspections on a routine basis to check for errors and make configuration changes. The problem with the former solution is that it is expensive to retain personnel for that purpose. The problem with the latter solution is that the technician will most likely be absent when the equipment suffers a breakdown or other serious problem. Another drawback to the latter solution is that the technician may be busy or otherwise involved at another equipment site, and thus, unable to respond to the equipment problem.
Some PBXs or ACDs may be equipped with another type of interface. This interface is a link to the telephone system through a single modem. Current technology usually has only one telephone line for remote maintenance. So, if one technician is already connected to the equipment or PBX through that on e single modem, a second technician that needs to perform a different operation, perhaps a software upgrade or a reconfiguration of resource, cannot access the PBX until the first technician is done. Moreover, this type of telephone interface is `passive` in that it does not seek out the technician when a problem arises, but rather waits until the technician dials into the equipment.
A major problem in the current technology with using the telephone interface is the lack of security. As the telephone interface is passive, it does not perform any kind of caller authentication or security screening on incoming calls. Thus, individuals known as `hackers` take advantage of this weakness in the system and break into the PBX system. Once inside, the hackers may change codes in the switching PBX, thus allowing them to make illegal long distance phone calls. Even worse, the hackers may attempt to sabotage the system by inserting a virus or deleting important system files.